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Thursday, April 15, 2010

Help Protect New Zealand Ecosystems

Following on from yesterdays ‘quickie’ comment on the very large wasp nest discovered in a Gisborne loft. This demonstrates quite well what can happen when animals or plants are introduced to new environments. They may find the new environment more suitable to them than the environment in which they evolved.

Wasps (German and common) were accidentally introduced to New Zealand, probably from the US and Europe. Both species form nests out of a papier-mâché like substance made from chewing wood. A large nest in their native lands would be beach ball size and contain four to five thousand wasps. Each winter the colony is reduced in number, perhaps leaving only the queen. The queen abandons the old nest to found a new nest in spring. However, in New Zealand the colonies are able to survive in large numbers through the mild New Zealand winter and a ‘super’ nest such as that found in Gisborne is formed by continued use of a nest for more than one season. The Gisborne nest may have contained as many as ten thousand wasps.

As well as the mild climate, wasps take advantage of the available food sources New Zealand provides; in particular the honey dew from the scale insect found on native beech trees. Wasp numbers in beech forest can reach extraordinary densities as many trampers will testify.

Wasps are not just a nuisance when you are having a barbecue or tramping through the bush. Many people have allergic reactions to stings that can be life threatening. Wasps are also an enemy to honey bees and will fight a ‘war’ with a honey bee hive in an attempt to steal the bee’s honey store. Bee keepers regard wasps as one of the major causes of reduced honey production. Wasps also damage the New Zealand ecosystems by preying on insects and have even been seen killing newly hatched birds.

You can help reduce wasp numbers and protect New Zealand’s ecosystems and New Zealanders by destroying wasp nests wherever you find them.